Automated test equipment (ATE) is used to test individual integrated circuits for compliance with predetermined specifications during manufacture. One of the most accurate testers available on the market has an overall AC accuracy of +/−55 picoseconds (ps). However, the existing testers are still not accurate enough to meet tSkew specs of +/−50 ps desired by certain manufacturers during DDR4 registered clock driver (RCD) tSkew testing.
It would be desirable to implement a design for testability (DFT)/design for manufacturing (DFM) method to adjust output skew timing.